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T. R. WILSON UNIFORM COMPRESSION INTERNAL COMBUSTION ENGINE Original Filed In 4. 1926 Sept. 13, 1932.

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art owing T. R. WILSON v S t 13, 1932 UNIFORI counsssron INTERNAL COMBUSTION ENGINE R 18,595

Mum Fuda lay 4. 1925 2 Sheets-Sheet 2 aubeuto'a sa [WW9 Reiuued Sept. 13, 1932 :UNITEPD STATES PATENT- OFFICE THEODORE R. WILSON, OI PESHASTIN, WASHINGTON, ASSIGNOR, BY DIRECT I HESNE ASSIGNMENTS, OI ONE-THIRD TO BROOKS WALKER, PIEDMONT, OAIJJ'OB- QNE-THIRD 1'0 HARRY E. KENNEDY, OF BERKELEY, CALHOBHIA, AND ONE-- 1 THIRD 'IO CLINTON L. WALKER, PIEDMONT, CALIFORNIA UNIFORM COMPRESSION INTERNAL -COMBUBTION ENGINE Original 110. 1,839,477, dated August 16, 1827, Serial No. 106,888, filed Kay 4, 1828. Application for reissue filed July 81, 1929. Serial No. 882,418.

' This invention relates to a uniform compression internal combustion engine and its object is to provide a mechanism of'this character so constructed that the maximum efficiency in operation is secured.

Extensive and accurate tests that I have made disclose the fact that there is a direct relation between the intake manifold pressure of an internal combustion engine and the 1 pressure in the cylinder of such engine; txat is, the pressure in the intake manifold, e-

tween the throttle of the carburetor and the interior of the cylinder, is always in direct I proportion to the pressure in the combustion chamber at the top of the compression stroke.

Therefore, broadly stated, the present invention resides in providing an internal combustion engine. cylinder with a movable abutment and affecting the adjustment of said abutment control by and in accordance with the intake manifold pressure. i

The advantages of the invention will be set forth in the detailed description which follows.

In the accompanying drawings:

Fig. 1 is a vertical sectional view of a portion of an internal combustion engine, having the invention applied thereto and I Fig. 2 is a'partial longitudinal sectional view through said engine.

Like numerals designate corresponding parts in 'both of the figures of the drawings.

It is to be understood that the drawings are merely illustrative. The particular arrangement .of parts may be varied within wide ranges without departing from the spirit of the invention. Referring to the drawings, 1 designates an engine having a. plurality of cylinders 2, formed therein. As each cylinder and its associated parts are substantially identical a description of one will serve as a description of all. The cylinder 4 is water-jacketed as indicated at 5 ,and is provided with auxiliary cylinders 6 of a diameter somewhat greater than the engine cylinders and out of line with respect ,to the engine cylinders. Pistons or compression I abutments7 are disposed in the cylinders 6,

u said abutments being cut away as indicated at 7 to permit the engine valves 8 to function.

A spark plug opening 9 is formed ,ad'aoent each of the valve clearance spaces 10. rock shaft 11 extends lengthwise of the engine and is supported in bearin s 12. The rock shaft carries a pluralit o cranks 1 ing in the same position with-respect to shaft 11 and these several cranks are connected by connecting rods 14 with the corresponding abutments 7. A crank arm 15 of the shaft 11 is enga ed by one end of the spring 16, the other encfof this spring being engaged with a bracket 17 upon the cylinder head 4.

Atsome point in its length-the shaft 11 is provided with a crank 18 which is somewhat longer than the cranks 13 and the crank pin 19 of the crank 18 is connected by a'connecting rod with the wrist pin 21 of a piston 22. Piston 22 has a working fit in a cylinder 23, the head of which is formed by the bottom 24 of an additional cylinder 25. piston 26 has a working fit in the cylinder 25. the last named piston carrying a housing 27 which has a hollow interior 28. A stout spring 29 bears between the top of the housing 27 the bottom 24 .of the cylinder and tends to thrust 75 *the piston 26 and its associated parts upward. A tube 30 is secured to and moves bodily with the housing 27, said tube having a tight working fit in the bottom 24 of the cylinder 25. and said tube having an open lower end which is parallel with the upper face of the piston 22. i

A suitable pump 32, preferably of the rotary gear type, forces oil through a pipe 33, from the sump of the engine, to the space within the cylinder 23 above the piston 22. An overflow pipe 34 leads from the interior of the cylinder 25, back to the engine oil sump. Conduit 35 leads from the space 36 beneath the piston 26 to a chamber 37. which is in communication with the intake manifold, of the engine through a conduit 38. Chamber 37 is spanned by a false bottom 39, having outlets 40, which are controlled by a gravity opening check valve 41. The space beneath the check valve is connected by a pipe 42 with the engine oil sump. A conduit 43 is connected to the pipe 42 and to an annular chamber 44 formed about the tube 30'and in the Y lower end or bottom of the cylinder 25. 1

and since the spring 29tends to thrust this piston upwardly it follows that this piston will occupy varying positions of vertical ad justment corresponding to the existing degree of pressure in the intake manifold. Since the tube 30 is connected rigidly to the piston 26 the'lower end of this tube will be caused to approach or recede from the top "of the piston 22, as it moves up and down.

With the engine running there will be a constant inflow of oil through pipe 33 under the influence of the rotary gear pump 32, which is engine driven. The only way of escape for this oil is upwardly through tube 30. The oil passing from the upper end of the tube overflows into the cylinder 25 and passes ofl through the overflow pipe 34 back to the sump.

Manifestly the rate of escape of the oil will be determined by the position of the lower end of the tube with respect to the top of the piston 22 and consequently the degree of pressure upon the piston 22 will likewise be determined by the position of this tube. Thus when the suction in the manifold is such as to draw piston 26 downwardly and thereby constrict the escape area of the oil, the pressure upon piston 22 will be increased and said piston will be thrust downwardly. Downward movement of piston 22 acts through the associated parts and against the tension of spring 16 to rock shaft 11 and move the abutments 7, in unison, downwardly, thereby reducing the effective compression space within the several cylinders.

Thus it will be seen that the effective compression space within the several cylinders is controllably varied under-the influence of variation in intake manifold pressures.

When the suction in the intake manifold decreases and the piston 26 rises under the influence of spring 35 increased escape area is provided and the oil pressure upon piston 22 is decreased, and spring 16v acts to lift the abut-ments 7 and correspondingly increase tlhe compression space in the several cyliners.

I have found in actual practice that the device of the present invention'is extremely sensitive and reliable in operation and that it will serve to maintain ideal compression pressure under all conditions. It is necessary that the abutments be raised almost instantly, wheneverthe throttle is suddenly opened. The present apparatus efliciently accomplishes this result.' The instant that the throttle is opened and the partial vacuum in the intake manifold is relieved the spring 29 quickly raises tube 30 and then the tension of spring 16 aided by pressure in the firing cylinder immediately forces the piston 22 to follow the control tube upwardly. Since the oil in cylinder 23 above piston 22 is always under more or less pressure and since tube 30 must be free to slide in 2-1 it is likely that a small amount of oil will travel upwardly past said tube and if it reaches the space beneath the piston 26 it might work check valve 41 will drop by gravity and permit any oil which has accumulated in the cylinder 37 topass downwardly into the tube 42. I

It is to be understood that the invention is not limited to the precise construction set forth; since the principles involved may be "embodied in apparatus of varying kinds. For

example the present construction has to do with poppet valve engines but it is manifest that the underlying principles are applicable to sleeve or rotary valve type engines.-

Therefore it is to be understood that the invention includes within its purview whatever changes fairly come within either the terms or the spirit of the appended claims.

Having described my invention what I claim is:

1. The combination with an internal combustionengine and its cylinders of a movable compression abutment and means under control of the intake manifold pressure of said engine for varying the position of said abutment in accordance with variations in said intake manifold pressure.

2. The combination with a multiple cylinder internal combustion'engine of an adjustable'compressionabutment for each of the said cylinders and means for simultaneously adjusting the position of all of said abutments under the influence of variations of intake manifold pressure. 1 e

3. The combination with a multiple cylinder internal combustion engine of a compression piston for each of said cylinders. a rock shaft having cranks attached to the several compression pistons and a piston for moving said rock shaft said piston being under control of intake manifold pressure.

4. The combination with a multiple cyl-' inder internal combustion engine of compression abutments for the several cylinders thereof, a piston the movement of which de termines the position of said compression abutments, a constant pressure fluid supply,

for action upon said piston, and an escape for said pressure fluid the capacity of which is varied under the influence of intake manifold pressure.

5. A structure as recited in claim 4 wherein said escape comprises an open ended tube movable toward and from said iston and a second piston by which said tu eis carried the last named piston being subjected to intake manifold ressure.

6. The combmation with a multiple cylinder internal combustion engine of abutment pistons constituting the com ression elements of the several pistons, a roc shaft having a plurality of cranks connected by connecting rods with the several abutments,- spring means tendin to rock said shaft in one direction, a flui pressure cylinder, a piston in said cylinder connected to the rock shaft acting to move said rock shaft against the tension of said spring, an en ine driven oil pump for pumping oil into t e cylinder to act upon t e piston, a second cylmder and piston one side of the last named piston bemg subjected to intake manifold pressure, a 5 ring acting upon the last named piston an tendin to move it ino position to the intake manifold pressure an an escape tube connected to the last named iston and constituting an escape for the oi the escape caacity of which is determined by the proximity of the end of said tube to the said piston. 7. A structure as recited in claim 6 wherem the oil which escapes from the escape tube overflows into the cylinder of the piston by which said tube is carried arid means for conductin the oil of overflow from said cyllnder to t e engine sump.

8. A structure as recited in claim 6 wherein the means for subjecting the piston to inv leakage past said tube to the engine sump.

11. A mechanism for varying the compression ratio of an internal combustion engine, which consists in the combination with a cylinder and its piston, of means controlled by variations in pressure during, the intake cycle for automatically increasing the com ression ratio when the pressure during the intake cycledecreases, and conversely for decreasing the compression ratio @when the pressure during the intake cycle increases, said compression ratio remaining a constant over cycles of like intake pressures regardless of speed variations of the engine.

12. The combination with the head, the

cylinder and the piston of an internal combustion engine, of means actuated by the difference in pressure betweenthe atmosphere and the ressure existing in the cylinder and manifold during the suction cycle of the engine for changing the clearance volume between the piston and the head.

13. The combination with the head, the cylinder and the piston of an internal combustion engine, of means actuated by the difference' in pressure between the atmosphere and the ressure existing in the cylinder and manifold during the suction cycle of the engine for changing the compression ratio.

. 14. The combination with the head, the cylinder and the piston of an internal combustion engine, of means actuated by the difference in pressure between the atmosphere and the ressure existing in the cylinder and manifold during the suction cycle of the engine for automatically changing the clearance space between the head and the piston during the compression cycle so as to either increase or decrease the compression ratio.

15. The combination with a multiple cylinder internal combustion engine having reciprocable pistons within said cylinder, an engine mainshaft, connections between said pistons and said en 'i'ne main shaft, and means for automatically changing the clearance volume in all the cylinders simultaneously and to the same degree by forces within said engine, whereby said clearance volume will increase automatically during an increase of engine torque and decrease automatically during a decrease of engine torque.

16. The combination with a multiple cylinder internal combustion engine having reciprocable pistons within said-cylinder, an engine main shaft, connections between said pistons and said engine main shaft, and means actuated by variations in internal engine pressures for automatically changing the clearance volume in the cylinders simul taneously and to the same de ee.

. THEODORE WILSON. 

